Internet search engines compete with one another to attract users as measured by the number of unique visitors each search engine attracts and by the number of searches and/or clicks that the users collectively execute on those search engines. These metrics, and others, allow advertisers on the search engine web pages to rate the search engines and allow the owners thereof to collect revenue from the advertisers.
It goes without saying that most users prefer to use search engines which produce fast, accurate, and complete results. If a particular search engine executes slowly, users experience frustration and are prone to navigate to another search engine while their initial search appears to be stalled, “hung,” or otherwise delayed. Moreover, if a search engine delivers query results which contain irrelevant information, the users also experience frustration as they navigate from one site to another without finding the information which they seek. Likewise, if the search engine delivers incomplete results the users (while perhaps never realizing that they possess incomplete search result) experience frustration as their search appears to have failed. Thus, they may find themselves trying many different search terms, different search engines, or giving up without locating the sought after information. Any combination of these, and other, problems may drive users from a search engine thereby diminishing the revenue stream which the search engine owner might otherwise earn.